MRI Shows Fructose Changes The Brain and May Cause Overeating

01/07/2013

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In a recent study released by the Journal of the American Medical Association, researchers used imaging tests to show that fructose triggers brain changes that may lead to overeating in a way that glucose does not. It’s a theory that faces a lot of criticism but certainly brings up questions.

After drinking a fructose beverage, the brain doesn’t register the feeling of being full in the same way it does with glucose. This was a small study and experts have by no means fully accepted the claim, but many contend that fructose may play a role in obesity, according to MyFoxDC.

Researchers gave 20 young, normal weight participants drinks containing glucose or fructose in sessions that were weeks apart. They used MRI scans to follow blood flow in the brain.

Glucose consumption seemed to promote satiety while fructose did not. Sugar is half glucose and half fructose. But it's a bit confusing because fructose is found in plant sources like honey, tree and vine fruits, flowers, berries, and most root vegetables. But in fruit it's also combined with fiber, which fills you up.

Its natural sources don't create near the issues that its processed state seems to produce. Fructose is added to beverages and processed foods in the U.S. in the form of high fructose corn syrup. The process starts off with corn kernels that are spun at a high velocity and combined with three other enzymes: alpha-amylase, glucoamylase, and xylose isomerase, so that it forms a thick syrup that's way sweeter than sugar and super cheap to produce.

Scans showed that drinking glucose "turns off or suppresses the activity of areas of the brain that are critical for reward and desire for food," said one study leader, Yale University endocrinologist Dr. Robert Sherwin. With fructose, "we don't see those changes," he said. "As a result, the desire to eat continues - it isn't turned off."